Filtering apparatus, method, and medium for multi-format codec

Abstract

Provided is a filtering apparatus, method, and medium for a multi-format codec, in which a blocking artifact of decoded video data is removed. The filtering apparatus includes a compression format detection unit, a block strength determination unit, a table determination unit, and a first filtering unit. The compression format detection unit detects a video compression format of the decoded video data. The block strength determination unit determines a block strength indicating a filtering strength with respect to the decoded video data according to the detected video compression format. The table determination unit determines a filtering table differently according to the block strength when the block strength is greater than a predetermined threshold. The first filtering unit performs filtering on the decoded video data in units of a block using the determined filtering table.

What is claimed is: 
     
       1. A filtering apparatus for a multi-format codec, which removes a blocking happening of decoded video data, the filtering apparatus comprising:
 a compression format detection unit to detect a video compression format of the decoded video data; 
 a block strength determination unit to determine a block strength indicating a filtering strength as being equal to or less than a first value when the detected video compression format is a first compression format, and as being greater than the first value when the detected video compression format is different from the first compression format; 
 a table determination unit to determine a filtering table differently when the block strength is equal to or greater than-4 the first value; and 
 a first filtering unit to perform filtering on the decoded video data in units of a block using the determined filtering table when the block strength is equal to or greater than the first value. 
 
     
     
       2. The filtering apparatus of  claim 1 , wherein the first value is 4, if the first compression format is H.264, and further comprising a second filtering unit performing predetermined filtering defined in H.264 when the block strength is less than 4. 
     
     
       3. The filtering apparatus of  claim 1 , wherein the first filtering unit comprises:
 a table storage unit to store predetermined filtering tables; 
 a matrix calculation unit to read-out a filtering table corresponding to table information determined by the table determination unit from the table storage unit and to perform matrix calculation on the read-out filtering table and input data to be filtered; 
 a rounding control unit to add a predetermined value to the matrix-calculated data; and 
 a shift operation unit to shift an output value of the rounding control unit by predetermined bits. 
 
     
     
       4. The filtering apparatus of  claim 3 , wherein when the video compression format is H.264, the predetermined value added by the rounding control unit is 4 and the predetermined bits shifted by the shift operation unit are 3 bits. 
     
     
       5. The filtering apparatus of  claim 3 , wherein the filtering tables are in 8×8 matrix forms. 
     
     
       6. The filtering apparatus of  claim 1 , wherein the block strength determination unit determines the block strength as being equal to 5 when the detected video compression format is WMV-9. 
     
     
       7. A filtering method for a multi-format codec, which removes a blocking happening of decoded video data, the filtering method comprising:
 detecting a video compression format of the decoded video data; 
 determining a block strength indicating a filtering strength as being equal to or less than a first value when the detected video compression format is a first compression format, and as being greater than the first value when the detected video compression format is different from the first compression format; 
 determining a filtering table differently when the block strength is equal to or greater than the first value; and 
 performing filtering on the decoded video data in units of a block using the determined filtering table when the block strength is equal to or greater than the first value. 
 
     
     
       8. The filtering method of  claim 7 , wherein the first value is 4, if the first compression format is H.264, and further comprising performing predetermined filtering defined in H.264 when the block strength is less than 4. 
     
     
       9. The filtering method of  claim 7 , wherein the performing of the filtering comprises:
 performing matrix calculation on a table corresponding to the determined table information and input data to be filtered; 
 adding a predetermined value to the matrix-calculated data; and 
 shifting an output value of the rounding control unit by predetermined bits. 
 
     
     
       10. The filtering method of  claim 9 , wherein the filtering tables are in 8×8 matrix forms. 
     
     
       11. A non-transitory computer-readable recording medium having recorded thereon a program for implementing a filtering method for a multi-format codec, which removes a blocking happening of decoded video data, the filtering method comprising:
 detecting a video compression format of the decoded video data; 
 determining a block strength indicating a filtering strength as being equal to or less than a first value when the detected video compression format is a first compression format, and as being greater than the first value when the detected video compression format is different from the first compression format; 
 determining a filtering table differently when the block strength is equal to or greater than the first value; and 
 performing filtering on the decoded video data in units of a block using the determined filtering table when the block strength is equal to or greater than the first value. 
 
     
     
       12. An apparatus for a multi-format codec for deblocking decoded video data, the apparatus comprising:
 a compression format detection unit to detect a video compression format of the decoded video data; 
 a block strength determination unit to determine a block strength indicating a filtering strength as being equal to or less than 4 when the detected video compression format is H.264, and as being equal to 5 when the detected video compression format is WMV-9; and 
 a table determination to determine a filtering table differently when the block strength is greater than or equal to 4. 
 
     
     
       13. The apparatus of  claim 12 , further comprising a first filtering unit to perform filtering on the decoded video data in units of a block using the determined filtering table when the block strength is greater than or equal to 4 to deblock the decoded video data. 
     
     
       14. The apparatus of  claim 13 , wherein the first filtering unit further comprises:
 a table storage unit to store predetermined filtering tables; 
 a matrix calculation unit to read-out a filtering table corresponding to table information determined by the table determination unit from the table storage unit and to perform matrix calculation on the read-out filtering table and input data to be filtered; 
 a rounding control unit to add a predetermined value to the matrix-calculated data; and 
 a shift operation unit to shift an output value of the rounding control unit by predetermined bits. 
 
     
     
       15. A method for a multi-format codec for deblocking decoded video data, the method comprising:
 detecting a video compression format of the decoded video data; 
 determining a block strength indicating a filtering strength as being equal to or less than 4 when the detected video compression format is H.264, and as being equal to 5 when the detected video compression format is WMV-9; and 
 determining a filtering table differently when the block strength is greater than or equal to 4. 
 
     
     
       16. The method of  claim 15 , further comprising performing predetermined filtering defined in H.264 when the block strength is less than 4 to deblock the decoded video data.